How Long Can I Leave My Car in Accessory Mode? (Explained)

The accessory mode in cars comes in handy at certain moments. With this feature, you can use your car’s accessories without running the engine. Back in the day, accessories are usable only when the engine runs. However, the question now is how long you can use it. So, you may ask:

How long can I leave my car in accessory mode? In general, you can leave your car in accessory mode for hours, and it won’t have any effect. However, it will only be so as long as you don’t use the accessories. If you do, it may cause your battery to drain so that you can leave it on for an hour or two max.

The accessory mode allows a specific amount of power to run the accessories. However, turning it on doesn’t get any power from the battery. As long as you limit the number of accessories you use, you can leave this on for a couple of hours without worries.

In this article, we’ll give you a walk-through of how this feature works. This way, you’ll have an idea of how it works and how to utilize it properly.

Without further ado, let’s get into it!

How Long Can I Leave My Car in Accessory Mode

Does Accessory Mode Drain Battery?

The accessory mode doesn’t drain the battery. If you turn it on, it won’t get power from your battery.

However, turning it on will allow the accessories to get power to run. Thus, the battery drain will entirely depend on the way you use the accessories.

If you turn this feature on but don’t use the accessories, you can leave it for hours, and it won’t hurt your battery.

On the other hand, it can drain your battery if you’re using the accessories simultaneously.

Since the accessory mode allows the accessories to run without the engine, it can drain the car’s battery quicker.

The car batteries recharge as the engines run. Thus, if the engine isn’t running, it can lead to battery draining if left on for hours.

Of course, it will depend on many factors. Among these are:

  • Your battery’s condition
  • The kind of accessory you use
  • The time of use

For instance, if you’re using air conditioning, heater, or navigation, it can lead to a quicker battery drain. On the other hand, stereos would be more power-efficient. However, it will still consume power nonetheless.

For this reason, it would be best not to leave your car’s accessory mode on, especially if you plan to do so for some time.

Can Your Car Battery Die While on ACC?

If you’re not using any accessories, it may not affect you at all. In short, your car battery is not likely to die while on ACC.

The answer to this question also depends on a variety of factors as well. However, in general, a car can die due to prolonged use of ACC.

Like I said earlier, accessory mode consumes power but does not recharge the battery since the engine is off. For this reason, the accessories can drain the battery.

Still, the hours of use before it dies would depend on many things. For instance, if you have a new battery and only use your stereo, it can be on for hours without draining the battery.

However, heavy car accessories can lead to battery draining, ending up in a powerless car.

car battery

How Long Before ACC Mode Drains Your Battery?

As I said earlier, the operating hours of your car on ACC mode depends on various factors. In general, a battery in a reasonable condition can hold your car for a couple of hours in ACC mode.

For this reason, take it as a rule of thumb to limit your car’s ACC mode on for only an hour or two.

If you plan to use it longer, it would be best to run your engine at hourly intervals.

This way, you can avoid draining your battery. Also, it’s by firing the engine that you can recharge your battery.

Most ACC modes have limited capacity. Thus, always make sure you check your status constantly to avoid draining it.

Car Battery Dies in Accessory Mode – What to Do?

Now, it can happen that your car battery would die due to prolonged use of ACC mode with accessories turned on.

The way to solve this is to charge your battery by running the engine. However, it’s not something you can do with a dead battery.

The most common solution to a dead battery is jump-starting. A jump-start is a set of jumper cables and another car with a functional battery.

You will connect your battery with another car’s battery to give it power. As your engine runs successfully, it should recharge your battery in the process.

If your car battery died down due to prolonged ACC mode use and no other issues, a jumpstart should be a sufficient answer to your problem.


In a nutshell, you can leave your car in ACC mode for hours, and it won’t hurt or drain your battery. However, it will only go as far as no accessories are running. With many or all accessories running, your battery may drain within a couple of hours.

Thus, it would be better for you to be mindful and limit your use of the ACC mode for an hour or two. If you used it for more extended periods, it would be best to run the engine in intervals.

Share on:

My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more